Process of treating silk.



' i g \U 1 UNITED STATES PATENT OFFICE. EDOUARD PAUL LOUIS SISLEY, OF'LYON, FRANCE, ASSIGNQR TO SOCIETA ANONIMA COOPERATIVA PER LASTAGIONATURA E LASSAGGIODELLE SETE ED AFFINI, OF

MILAN, ITALY, A CORPORATION OF ITALY;

PROCESS OF TREATING SILK.

Specification of Letters Patent.

Patented Feb. 11, 1908.

Application filed January 16. 1906. Serial No. 296.426.

To all whom it may concern:

Be 1t known that I, EDOUARD PAUL L6U1s SIsLEY, chemist, a citizen of the Republic of specification.

treated for this This invention has reference to a novel process of treating silks and pertains artlcularly to. a process of treating silks w ich have been impregnated, for instance, with salts of tin, for the purpose of 'preventin spontaneous changes to which such .sil yarns, Woven fabrics, or goods are subject when exposed to light, heat, and atmospheric influences. Accordingly, this process is applied after the silks have been impregnated with the salts. Heretofore silk has been purpose with a dilute solutlon of sulfocyamc acid or its salts.

It is the special object of this invention to provide a process for obtaining a higher degree of tensile strength and elasticity of the silks uicker and in a more satisfactory manner 1; an with the above mentioned substances. I have discovered that thio-urea, its salts, and derivatives are compounds by the use of which this desirable result is obtained. a

'In carrying out my novel process I substantially proceed as follows. The dyed skeins or hanks-0f silk are immersed in a dilute solution of thio-urea, its salts, or derivatives to which solution may be added a small quantity of an acid, for instance 2 rams of citric acid per liter of the solution, in order to maintain the scroop or crisp sound while the skeins or hanks so treated are ex osed to the air and dried. The quantlty o thio-urea, its salts, or derivatives employed in such a bath may vary 10 grams of thio-urea per liter may be used. Woven fabrics likewise may be treated'by immersing them in a bath of the above named substances or the solution may be sprayed thereon or any other suitable method may be employed to impregnate the woven fabrics with a solution of the above described chemicalagents. The solution of thio-urea may also be mixed with various.

sizes and the treatment of the goods with thio-urea in combination with the known methods of sizing whereby the goods are at once. finished likewise is a feature of this affected by rust marks.

invention and comes within the scope of same.

The novel process of treating silks with thio-urea im arts to the impregnated yarns of fabrics a igh degree of resistance to the action of atmos heric influences but without presenting the eficiency of fabrics which are The novel process further imparts to the goods the property ofresisting perspiration whereby the formation of stains is prevented in the single threads or fabrics while under the influence of perspiration or of substances containing chlorids. The protecting effect of this treatment is explained by the fact that thio-urea, its salts,

than the silk fiber in the presence of metallic salts such as tin salts leaving then the fiber in a condition of unimpaired strength and increasing its elasticity. The color of the silk fibers thus treated is not affected and remains constant. Tests made with the serimeter verified this statement.

Having thus described my invention I claim as new and desire to secure by Letters Patent L'Process of increasing the tensile strength and elasticity ofsilks weighted with metallic salts consisting in immersing the silks in a slightly acidulated bath of thio-, urea compounds, and drying same on the fiber. y

2. Process of increasing the tensile strength and elasticity of silks weighted with tin salts consisting in immersing the silks in a slightly acidulated bath of thiourea and drying same on the fiber.

'3. Process of increasing the tensile strength and elasticity of silks weighted with tin salts consisting in immersing the silks in a dilute solution of thio-urea slightly acidulated with citric acid, and drying same on the fiber.

'4. Process of increasing the tensile strength and elasticity of silks weighted 70 and derivatives are more easily oxidized 

